FWIW, my new-in-box Magura rotors are .075" thick, so your .80" rotors would be more suited to a Chevy Since I know you meant .080-.10", that's going to be too thick to fit in your calipers even with new pads retracted fully. You'd then have to machine every set of pads thinner, which is way too much trouble and opens up service life issues.

More mass in the rotor itself will absorb more heat. In that case the particular Magura rotors I have ($11 each for 203mm from HnR at Christmastime) would probably suit you as well as any. There aren't going to many choices for what you want, since most people want lighter rotors...but the inexpensive rotors will typically be heavier (more mass).

That said, the fancy two-piece stuff can cool better, and so may be of more benefit.

Hope vented floating disc. Those are some proper, heavy duty DH rotors. In terms of ability to dissipate/withstand heat, you can't do much better. They are also among the thickest rotors produced at 3mm (IIRC) -> they should therefore be among the most bend-resistant rotors out there. Don't know about impact resistance, though.